Harry Redknapp broke Queens Park Rangers' transfer record for the second time this month with the £12.5m signing of the central defender Christopher Samba, as he sought to reshape his squad for the relegation battle ahead on a deadline day of frantic activity at the club.

Samba became the 27th purchase of Tony Fernandes' 17-month tenure at Loftus Road when the chairman met the value of the release clause on his contract at Anzhi Makhachkala in the Russian League. The 28-year-old Congolese joins on a four-and-a-half-year contract and he follows the striker Loïc Rémy to west London. Rémy arrived a little over two weeks ago from Marseille for £8m which, at the time, was a record fee for QPR.

Samba's adviser, Walid Bouzid, said that his client's weekly wage was less than £100,000 a week but added that the money was certainly "Premier League-sized" and did not include a clause to decrease it if the club were relegated to the Championship. The deal for Samba, factoring in the transfer fee and wages, is believed to be costing QPR £28m.

Rémy's deal is worth a basic £75,000 a week, excluding a large survival bonus, and, when the fee is accounted for, the club stand to pay more than £25m on him alone, even if there is a release clause in the deal, allowing rivals to sign him at a cut price if QPR were to go down.

The package for Samba has seen the club up the ante further and it reinforced the high-stakes survival game that they are playing. Nobody can countenance the financial implications of failure. Fernandes has already suggested that he would walk away if the club went down.

QPR's efforts to strengthen further took in drama and controversy, particularly with their attempt to take the striker Peter Odemwingie from West Bromwich Albion. Odemwingie had made no secret of his desire to leave the Hawthorns and link up with Redknapp in London, giving regular bulletins from his Twitter account as QPR had offers for him rejected.

He then turned up at Loftus Road in the evening only for West Brom to issue a statement in which they said there was no agreement in place for him to move or, even, to discuss doing so with QPR. The London club refused him entrance to the stadium, claiming it would have been disrespectful to West Brom to have admitted him, and with the implicit suggestion being that Odemwingie had acted alone.

As the saga entered the final hour of the window, Odemwingie indicated that his hopes of getting the transfer hinged on West Brom signing a replacement for him. QPR had earlier missed out on the signing of the Stoke City forward Peter Crouch.

QPR were confident of completing deals for the Tottenham pair Jermaine Jenas and Andros Townsend, even if a move for a third White Hart Lane player, David Bentley, fell apart when the club chairman, Daniel Levy, demanded a prohibitively high fee. Bentley is out of contract in 2014 and Levy has been consistently determined to recoup a portion of the £15m that he paid for him in 2008.

Jenas was in talks over an 18-month deal at Loftus Road, which would take him up to the end of his Tottenham contract while Townsend was set for a loan move until the end of the season.

Redknapp had said that QPR would be doomed if they did not strengthen and he was delighted at the capture of Samba. "Tony Fernandes deserves a lot of credit for this one – he has worked so hard on bringing him in," Redknapp said. "I was speaking with him a month ago and he asked me who I would want to sign if Ryan Nelsen left, he asked me to give him a couple of names.

"I said to him, 'Well, these aren't possible to get but if you're asking me who I'd have, I'll give you a couple of players'. One of them was Chris Samba. The next thing I know he's telling me that he's working on bringing him in. It's amazing. Chris is just what we need. He's a monster. Great in the air, quick, a leader, strong, fantastic in both boxes, hard as nails. He's a proper centre-half."

Redknapp has loaned the midfielder Ale Faurlín to Palermo and the striker DJ Campbell to Blackburn Rovers.